Regulex

Regulex is an open-source, regular expression parser and visualizer. It's available online, can be embedded in other websites, or the code can be self-hosted as a JavaScript tool.

FEATURES

• Written in pure JavaScript. No backend needed.
• You can embed the graph in you own site through html iframe element.
• Detailed error message. In most cases it can point out the precise syntax error position.
• No support for octal escape. Yes it is a feature. ECMAScript strict mode doesn't support octal escape in string,but many browsers still support octal escape in regex. I make things easier. In regulex, DecimalEscape will always be treated as back reference. If the back reference is invalid, e.g. /\1/?/(\1)/?/(a)\2/,or DecimalEscape appears in charset(because in this case it can't be explained as back reference, e.g. /(ab)[\1]/), Regulex will always throw an error.